Automated RFID reader detection

ABSTRACT

Carrying out a calibration cycle on one or more components in a local area network, the network including a plurality of Radio Frequency Identification (RFID) readers and the calibration cycle including exchanging, between RFID readers or other components of the local area network, distances between RFID readers calculated by one or more other components of the local area network.

This application is a continuation of U.S. application Ser. No.12/409,477, filed on Mar. 23, 2009. The entirety of that parentapplication is incorporated by reference herein.

BACKGROUND

The field of invention regards automated spatial detection of hardwarein a network. More specifically, embodiments include devices, methods,and systems that are automated to detect or determine the presence,orientation or spacing of RFID readers.

Radio Frequency IDentification (RFID) is used in various applications intoday's commerce. RFID technology involves the use of movable RFIDtransponders or “tags,” movable or stationary RFID readers to detect andrecord the presence of objects represented via the RFID tags, and asupport network to capture and reconcile the data received by the RFIDreaders.

RFID readers are used to sense the presence of an RFID tag by sensingradio frequencies rebounding or backscattered from the RFID tag. Oncesensed, an RFID reader may use the detected radio frequency signal toindicate the presence and identity of a tag. This presence may be usedby a network coupled to the RFID reader for recording the presence ofthe RFID tag at a point in time or to charge an account associated withthe RFID tag.

RFID tags comprise an antenna and control logic that work together touniquely announce the tag. RFID tags may be powered or unpowered.Unpowered tags are referred to as passive RFID tags while tags withtheir own power source are referred to as active RFID tags. In eitherinstance, an RFID tag acknowledges its presence through electro-magneticwaves in the radio frequency band. These waves acknowledge the tag'spresence to any RFID reader within range of receiving the tag's radiofrequency waves. The tag's radio frequency waves or signal can includemodifying and backscattering a radio frequency signal originallyreceived from an RFID reader. An RFID tag may also periodically generateradio frequency signals to announce its presence. Whether a tag isactive or passive, its radio frequency signals may be detected by one ormore RFID readers.

BRIEF SUMMARY

Embodiments include network devices, systems, methods, and computerreadable medium. The network devices may include a microcontroller thatoperates at a first network component of a local area network. Thenetwork device may further include an antenna in communication with themicrocontroller where the antenna may be configured to at least transmitor receive radio frequency electro-magnetic waves. In this example, themicrocontroller may be configured to spatially locate one or morefiducial network components of a local area network in which themicrocontroller is a member. The spatial location may be determined byreceiving a unique identifier for a first fiducial network component,receiving a wireless signal from the first fiducial network component,determining a physical distance between the first network component andthe first fiducial network component, and updating a registry with thedetermined physical distance and perhaps the orientation. In certainembodiments, the network component may be an RFID reader and the uniqueidentifier may be an IP address, MAC address or other uniquedesignation.

Embodiments may also include a method wherein operating instructions ata microcontroller of a first network component of a local area networkare carried out. When these instructions are carried out, themicrocontroller may spatially locate one or more fiducial networkcomponents in a local area network in which the microcontroller is amember. When carrying out the instructions, the microcontroller maydetermine the spatial location of one or more fiducial networkcomponents by receiving a unique identifier for a first fiducial networkcomponent from the one or more fiducial network components, receiving awireless signal from the first fiducial network component, determining aphysical distance between the first network component and the firstfiducial network component, and updating a registry with the determinedphysical distance or orientation, or both.

Embodiments may also include computer readable storage medium havingstored thereon instructions, which, when executed by a microprocessor,cause the microprocessor to carryout steps to spatially locate one ormore fiducial network components of a local area network in which themicrocontroller is a member. These steps may include receiving a uniqueidentifier for a first fiducial network component from one or morefiducial network components, receiving a wireless signal from a firstfiducial network component, determining a physical distance between afirst network component and the first fiducial network component, andupdating a registry with the determined physical distance or orientationor both.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a diagram of a local area network with three fiducial networkcomponents.

FIG. 2 is a diagram of the local area network of FIG. 1 where one ormore of the fiducial network components have been repositioned.

FIG. 3 is a diagram of the local area network of FIG. 1, after one ormore fiducial network components have been repositioned within the localnetwork, and after a fourth fiducial network component has been added tothe local network.

FIG. 4 shows a loading dock and warehouse with a local network ofingress/egress RFID readers and storage RFID readers.

FIG. 5 shows the loading dock and warehouse of FIG. 4 after the additionof an ingress/egress RFID reader and the addition and repositioning ofstorage RFID readers in the warehouse.

FIG. 6 is a block diagram of an exemplary RFID reader or networkcalibration module.

FIG. 7 is a block diagram of an exemplary RFID reader.

FIG. 8 is a functional block diagram of acquisition and control logic ofan exemplary RFID reader or network calibration module.

DETAILED DESCRIPTION

Local area networks may comprise servers, databases, sensors, readers,and other components. These components may be added and removed from thenetwork as network demands and requirements change. These components maycommunicate with other components in the networks through wired andwireless connections and through various means and protocols. Whencomponents are added or deleted the local area network may recognizethat a component is no longer in the network or may also recognize thata new component has been added to the network. Identifying whichcomponents are in the network can be beneficial for managing componentswithin the network, for managing data within the network, and forresolving conflicting input or data from the various components of thenetwork.

In addition to identifying which components are part of the localnetwork, components of the network may also be configured to account forthe physical spacing or location of each of the components within thenetwork. Knowing and accounting for the physical spacing of thecomponents may be beneficial for proper performance of the networkcomponents and may also be beneficial to detect and reconcileunanticipated movement of components within a network. For example, whenmultiple RFID readers receive signals from the same RFID tag—a“crossread”—the RFID readers may need to arbitrate whether to assign thesignal to a single RFID reader and what factors may be considered whenassigning a signal to a specific RFID reader. This arbitration processmay include detecting signal strength, determining which RFID readersreceived the signal, and considering the relative spacing of RFIDreaders to evaluate which RFID reader is the closest to the signal andthe RFID tag.

FIG. 1 shows a local area network 100 comprising three fiducial networkcomponents 120 a-120 c and a calibration device, arbiter, or calibrationmodule 150. The fiducial network components (or fiducial components) maybe servers that assist remote clients, they may also be RFID readersthat are used to monitor a retail facility, loading dock, warehousefacility, or some other location. There may be other types of fiducialcomponents as well. A common attribute of the fiducial components may bethat their location in space or their location relative to otherfiducial components may need to be known in order for the fiducialcomponent to serve an intended function or purpose. In embodiments, thefiducial components may serve as reference markers that may monitormovement among and between the components.

The local networks in which the fiducial components 120 and arbiter 150reside may also include other equipment, such as: routers, cabling,remote antennas, personal terminals, and other types of components. Allof this equipment may communicate with each other using wired andwireless methods.

Three fiducial components in a local area network 100 are shown at atime T1 in FIG. 1. At time T1, the distance between these three fiducialcomponents is reflected by D1-D3. FIG. 2, by comparison, shows the samethree fiducial components of the local area network 100 of FIG. 1 at atime T2. As can be seen, the three fiducial components 120 a-120 cremain in the local network, but their location has changed relative totheir surroundings and relative to one another. The new distancesbetween the fiducial components, at time T2, are now reflected by D4-D6.

FIG. 3 shows the local area network 100 of FIG. 1 at time T3. As can beseen, the network 100 now includes four fiducial components 120 a-120 d.Also, the positions of each of the fiducial components have changedrelative to each other. The new distances between the fiducialcomponents 120 are now reflected by D7-D12.

One or more of the fiducial components 120 and the arbiter 150 may beindividually configured to recognize the presence of each of thefiducial components 120 in the local area network 100 and to determinethe spatial relationship between the fiducial components. For example,when a fiducial component is added, a registry listing all of thefiducial components in the local area network or all of the componentsin the local area network may be updated to reflect the addition andrelative position of the fiducial component. Likewise, when a fiducialcomponent or other device is removed from the local area network, theregistry listing of the network may be updated to reflect that change aswell.

Embodiments may also include systems, methods, and devices thatperiodically determine the distances between one or more classes ofcomponents in the local area network, i.e. a network calibration cycle.For example, the distance between each of the fiducial components may behelpful information for the functioning or operation of the network.Periodically, the arbiter or calibration device 150, or the fiduciarycomponents 120 themselves, may sense the distance between some or all ofthe selected components and may then update a registry reflecting thecurrent status of the network. This registry may be stored in each ofthe fiducial components 120 as well as in the calibration device 150.

A network calibration cycle may occur many times per second or may bespaced to occur a few times per hour or day in order to save overhead inthe network. The process of carrying out the calibration cycle mayinclude a combination of wired and wireless communications between thefiducial components, devices associated with the fiducial components,and the calibration device 150. These communications may includeself-identifying an IP address, MAC address or other unique identifier,broadcasting this address to some or all components in the network, andusing radio frequency telemetry to determine the distances betweenfiducial components in the network. This distance detection may includegenerating radio frequency waves and listening for responses from eachof the fiducial components in the network. Upon receipt of the responsesto the radio frequency broadcasts, distances between each of thefiducial components may be calculated and a registry reflecting thesedistances may be updated. This registry, which may comprise networkcomponents and component distances, may be shared amongst all of thecomponents and may also be stored at a central location and thecalibration device 150. As needed, the registry may be accessed to makeupdates and also when needed to perform functions of the local areanetwork or functions of components within the local area network.

FIG. 4 shows a loading dock and warehouse area with a network of RFIDreaders that may employ inventive embodiments. Visible in FIG. 4 areingress/egress RFID readers 120, warehouse RFID readers 421 a-421 c,warehouse shelving 430 a-430 c, warehouse entrance 410, arbiter 150, andmerchandise paths 401 and 402. In this embodiment, parts merchandise orother material may enter the warehouse through entrance 410 and followpaths 401 or 402 to the shelving 430 in the warehouse. When thesematerials have been labeled with RFID tags, they can be trackedthroughout their lifecycle at the warehouse. When RFID tags are read bymultiple RFID readers, an arbitration process may be used to determinewhich RFID reader is the closest. By determining which RFID reader isthe closest, the material may be more accurately located moving withinthe warehouse and during its storage there as well. The tag arbitrationprocess may employ determining the signal strength of an RFID tag ateach RFID reader and, considering the distances between the RFIDreaders, determining which RFID reader the RFID tag is closest to. Otherarbitration techniques may include phase, angle, multipath reflections,read counts, and timing.

Embodiments of the tags may include passive tag circuitry consistentwith magnetic induction (near field RFID) and electromagnetic (EM) wavecapture (far field RFID). In the magnetic induction circuit a coilcoupled to a capacitor may be used to accumulate a charge that may thenbe used to power the circuitry of the tag and to create a magnetic fieldthat can be read by a nearby reader. In the electromagnetic wave capturecircuit a dipole antenna may be used to receive energy as alternatingpotential from a reader in order to accumulate energy to power itsapplicable circuitry. The antenna of this EM passive circuitry may betuned to a frequency that can absorb signals at that frequency andreflect signals when there is a mismatch. These reflected mismatchedwaves may then be read by an antenna of a reader. Information may beencoded on this mismatched signal through modifications in the impedanceover time thereby reflecting back more or less of the signal to thereader.

FIG. 5 shows the loading dock and warehouse area of FIG. 4 after theaddition of a third ingress/egress RFID reader 120, the addition of afourth warehouse shelving unit 530 d and accompanying RFID readers 521 d1 and 521 d 2, and the repositioning of shelving 430 a-430 c. Thesechanges in the loading dock area and warehouse area enable twofunctional warehouse entrances 410 to be created and many moremerchandise paths 501-503 to become available. These changes have alsoaffected the distances between the RFID readers.

In embodiments, the revised distances between the RFID readers may beautomatically sensed, determined, and recorded. This calibration cyclemay continue in the network many times per second and may also beconducted over longer periods of time, including hourly, daily and evenlonger. The RFID readers 120 may comprise active or passive RFID tagsthat may be sensed by other RFID readers in the network. When an RFIDreader senses that a new RFID reader has entered into the network orthat an RFID reader has moved its position, the RFID reader may send aquery to the new or changed RFID reader requesting that the new orchanged reader identify its IP or MAC address and to designate whichRFID tag or RFID signal identifies the reader. Likewise, the moved RFIDreader may auto announce its presence or that it has changed itslocation. Upon receipt of the response to the query or the announcementfrom the new/moved RFID reader, the existing RFID reader may generate aradio signal and listen for an RFID signal that coincides with thenew/changed RFID reader. Upon receiving the responsive signal, the RFIDreader may update the network registry of RFID readers for use by othercomponents within the network.

The arbiter or calibration device 150 may also be used to automaticallydetermine changes with RFID readers in the network. This device may be astand-alone unit and may also be integrated with one or more of the RFIDreaders in the network. The calibration cycle may be carried out by themethods, devices and systems supported herein by the calibration deviceor an RFID reader or a combination of the two.

When an RFID reader is new or its position has changed, the new/changedRFID reader may announce its presence to the network by providing its IPand/or MAC address to other components in the network. Upon receivingthis address, the other components may generate a radio signal andlisten for a response RFID signal from an RFID tag that coincides withthe new/changed RFID reader. Upon receiving the response, the existingRFID readers may update the network registry of RFID readers for use bythemselves and other components within the network.

FIG. 6 is a block diagram of an RFID reader or calibration module ofinventive embodiments. The RFID reader or calibration module 600 mayinclude a power source 640, a microcontroller with memory and storage650, an antenna 670, radio frequency receiver units 662 and 664, anactive radio frequency control circuit 663, and a passive radiofrequency control circuit 661. These components may communicate witheach other or receive power through the bus 680 or through other circuitconnections. Also, in some embodiments, there may be multiple antennasfor the RFID reader, where each antenna may be associated with a singlecontrol circuit or radio frequency receiver.

FIG. 7 is a block diagram of an RFID reader of inventive embodiments.The RFID reader 700 may include a power source 740, a microcontrollerwith memory and storage 750, an antenna 670, a transceiver 760, and twoRFID tags—an active tag 793 and a passive tag 791. The passive tag mayinclude controls 792 and an antenna 670 while the active tag 793 mayinclude an antenna 670 as well as power and controls 794. The storage750 of the reader 700 may include in memory, unique identifications ofthe passive RFID tag 791 and the active RFID tag 793. These uniqueidentifications may include the MAC address of the reader in a User Datafield.

The unique identifiers used to identify the readers of FIGS. 6 and 7 maybe associated with single readers as well as to groups of readers. Forexample, several readers may identify themselves as belonging to asingle entrance or portal and may not self-identify beyond the group. Inso doing, specific portals or entrances may be more simply accounted forby the network as a whole. Also, other radio protocols may be usedduring self-discovery. For example, Bluetooth protocols may be usedalong with signal strength. Still further, UDP communication methods orother methods may be used within the network to communicate betweenreaders or other components. Thus, both wireless and wiredcommunications may be employed.

FIG. 8 is a functional block diagram of acquisition and control logic ofan exemplary RFID reader or network calibration module. The calibrationcycle described herein may be carried out using these or other steps andmay be carried out in the provided sequence as well as in othersequences. Moreover, some of the steps may be omitted, combined, andmodified while remaining within the spirit and scope of this disclosureand the invention.

The calibration cycle of FIG. 8 may start at power-up for an RFID readeror calibration module. The cycle may also start upon sensing thepresence of a new RFID reader in the local area network. When the cyclehas begun, the RFID reader may transmit a calibration RF signal as shownin 802 and listen for a response as shown in 803. Upon receivingresponses from the calibration RF signal, the RFID reader may comparethe received responses to a registry of known readers and may determineif the response comes from a new RFID reader. These actions are shown in804 and 805. If a new RFID is identified, the RFID reader or calibrationmodule may send a query to the new RFID reader to identify itself, asshown in 806. The new RFID reader may respond with its IP or MAC addressand this response may be received by the RFID reader or calibrationmodule carrying out the calibration, as shown in 807. The signalstrength of this response may be measured and compared with the signalstrength of other RFID readers in the network in order to determine therelative distance to the new RFID reader.

As shown in 808, this new information may also be used to update aregistry of network components where the registry is retained at theRFID reader or at various components in the local area network. An RFIDreader may complete a reverse MAC-IP lookup in order to obtain theregistry of neighboring RFID readers.

At 809, the RFID reader may send a radio signal to calibrate itsposition with each of the other RFID readers in the network. This signalmay include a personal identification of the RFID reader, e.g. “I amreader R, and I see readers X, Y, and Z in this proximity.” Uponreceiving the responses back from the other RFID readers, thecalibrating RFID reader or the calibration module may determine thedistance to all of the readers and may compare these distances to knownRFID reader positions. When distances between readers is known, thisinformation may be used by the readers when deciding which reader anRFID tag is closest to when the tag is read by multiple readers.

In some instances, more than one RFID reader may be conducting acalibration cycle. In this case, the RFID readers conducting thecalibration or the calibration module may exchange distances to otherRFID readers that have been calculated in order to verify the accuracyof the calibration.

At 811, if none of the positions of the RFID readers have changed, thena period of time may lapse before beginning the next calibration cycle.If RFID reader positions have changed, then the registry of known RFIDreaders may be updated, as shown at 812. Thus, the steps may be used toidentify the presence, absence, additional or removal of an RFID reader.

The tags and readers may use various frequencies including lowfrequencies (30-500 kHz), high frequencies (10-15 Mhz) and ultra highfrequencies (850-950 MHz, 2.4-2.5 GHz, AND 5.8 GHz). The frequencychosen for operation may depend on the intended us of the RFID systemwhere high frequencies may be more useful for short read times whilelower frequencies may be more useful in environments with high metalsand fluid environments and when larger spiral inductors may be used inthe tags.

Standards that may be employed, at least in part, include ISO 11784-85,ISO 14223, ISO 10536, ISO 14443, ISO 15693, and ISO 1800.

Other embodiments are also encompassed. For example, an additionalconfidence algorithm may be used to assess the accuracy of the distancescalculated for each of the readers. Also, in addition to radio frequencyidentification, global positioning algorithms or techniques may be usedto locate the fiducial network components, including the RFID readersdiscussed throughout. Still further, should a fiducial network componentnot be detected, but is known to be present in the network, the otherfiducial components or the arbitration module may extrapolate thefiducial component's position from previous known positions in order to“self-heal” the network and reduce the likelihood of tag misreads. Also,multiple antennas may be placed on single sides of a polygonal RFIDreader. Depending upon which antenna's signals are received from theother RFID readers in the network, the relative orientation of the RFIDreaders relative to one another can be deduced.

As will be appreciated by one skilled in the art, the present inventionmay be embodied as a system, method or computer program product.Accordingly, the present invention may take the form of an entirelyhardware embodiment, an entirely software embodiment (includingfirmware, resident software, micro-code, etc.) or an embodimentcombining software and hardware aspects that may all generally bereferred to herein as a “circuit,” “module” or “system.” Furthermore,the present invention may take the form of a computer program productembodied in any tangible medium of expression having computer-usableprogram code embodied in the medium.

Any combination of one or more computer usable or computer readablemedium(s) may be utilized. The computer-usable or computer-readablemedium may be, for example but not limited to, an electronic, magnetic,optical, electromagnetic, infrared, or semiconductor system, apparatus,device, or propagation medium. More specific examples (a non-exhaustivelist) of the computer-readable medium would include the following: anelectrical connection having one or more wires, a portable computerdiskette, a hard disk, a random access memory (RAM), a read-only memory(ROM), an erasable programmable read-only memory (EPROM or Flashmemory), an optical fiber, a portable compact disc read-only memory(CD-ROM), an optical storage device, a transmission media such as thosesupporting the Internet or an intranet, or a magnetic storage device.Note that the computer-usable or computer-readable medium could even bepaper or another suitable medium upon which the program is printed, asthe program can be electronically captured, via, for instance, opticalscanning of the paper or other medium, then compiled, interpreted, orotherwise processed in a suitable manner, if necessary, and then storedin a computer memory. In the context of this document, a computer-usableor computer-readable medium may be any medium that can contain, store,communicate, propagate, or transport the program for use by or inconnection with the instruction execution system, apparatus, or device.The computer-usable medium may include a propagated data signal with thecomputer-usable program code embodied therewith, either in baseband oras part of a carrier wave. The computer usable program code may betransmitted using any appropriate medium, including but not limited towireless, wireline, optical fiber cable, RF, etc.

Computer program code for carrying out operations of the presentinvention may be written in any combination of one or more programminglanguages, including an object oriented programming language such asJava, Smalltalk, C++ or the like and conventional procedural programminglanguages, such as the “C” programming language or similar programminglanguages. The program code may execute entirely on the user's computer,partly on the user's computer, as a stand-alone software package, partlyon the user's computer and partly on a remote computer or entirely onthe remote computer or server. In the latter scenario, the remotecomputer may be connected to the user's computer through any type ofnetwork, including a local area network (LAN) or a wide area network(WAN), or the connection may be made to an external computer (forexample, through the Internet using an Internet Service Provider).

The present invention is described below with reference to flowchartillustrations and/or block diagrams of methods, apparatus (systems) andcomputer program products according to embodiments of the invention. Itwill be understood that each block of the flowchart illustrations and/orblock diagrams, and combinations of blocks in the flowchartillustrations and/or block diagrams, can be implemented by computerprogram instructions. These computer program instructions may beprovided to a processor of a general purpose computer, special purposecomputer, or other programmable data processing apparatus to produce amachine, such that the instructions, which execute via the processor ofthe computer or other programmable data processing apparatus, createmeans for implementing the functions/acts specified in the flowchartand/or block diagram block or blocks.

These computer program instructions may also be stored in acomputer-readable medium that can direct a computer or otherprogrammable data processing apparatus to function in a particularmanner, such that the instructions stored in the computer-readablemedium produce an article of manufacture including instruction meanswhich implement the function/act specified in the flowchart and/or blockdiagram block or blocks.

The computer program instructions may also be loaded onto a computer orother programmable data processing apparatus to cause a series ofoperational steps to be performed on the computer or other programmableapparatus to produce a computer implemented process such that theinstructions which execute on the computer or other programmableapparatus provide processes for implementing the functions/actsspecified in the flowchart and/or block diagram block or blocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof code, which comprises one or more executable instructions forimplementing the specified logical function(s). It should also be notedthat, in some alternative implementations, the functions noted in theblock may occur out of the order noted in the figures. For example, twoblocks shown in succession may, in fact, be executed substantiallyconcurrently, or the blocks may sometimes be executed in the reverseorder, depending upon the functionality involved. It will also be notedthat each block of the block diagrams and/or flowchart illustration, andcombinations of blocks in the block diagrams and/or flowchartillustration, can be implemented by special purpose hardware-basedsystems that perform the specified functions or acts, or combinations ofspecial purpose hardware and computer instructions.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a,” “an” and “the” are intended toinclude plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specific thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operation, elements,components, and/or groups thereof.

The corresponding structures, material, acts, and equivalents of allmeans or steps plus function elements in the claims below are intendedto include any structure, material or act for performing the function incombination with other claimed elements are specifically claimed. Thedescription of the present invention has been presented for purposes ofillustration and description, but is not intended to be exhaustive orlimited to the invention in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill without departingfrom the scope and spirit of the invention. The embodiments were chosenand described in order to best explain the principles of the inventionand the practical application, and to enable others of ordinary skill inthe art to understand the invention for embodiments with variousmodifications as are suited to the particular use contemplated.

What is claimed is:
 1. An automatic method of calibrating networkcomponents comprising: repeatedly and automatically carrying out afiducial component calibration cycle using radio frequency telemetrybetween stationary fiducial components in a local area network todetermine the present position of one or more stationary fiducialcomponents in the local area network, the network including a pluralityof Radio Frequency Identification (RFID) readers, the calibration cycleincluding exchanging, between stationary RFID readers of the pluralityor other fiducial components of the local area network, one or moredistances between stationary RFID readers of the plurality, the one ormore distances calculated by one or more other components of the localarea network using radio frequency telemetry between stationary fiducialcomponents of the local area network, and at at least one of thestationary RFID readers receiving the distances in the calibration cycleexchange and verifying the accuracy of the exchanged calculateddistances between stationary RFID readers of the plurality in the localarea network.
 2. The method of claim 1 wherein the calibration cycleincludes periodically exchanging, between first and second stationaryRFID readers of the plurality, distances between stationary RFID readersof the plurality calculated by one or more other components of the localarea network, and wherein the one or more other components includes atleast a third stationary RFID reader of the plurality.
 3. The method ofclaim 1 wherein the method further comprises: an RFID reader in thelocal area network periodically sending a telemetry radio signal to thelocal area network to calibrate its position with each of the other RFIDreaders in the local area network.
 4. The method of claim 3 wherein theradio signal includes a personal identification and a list of other RFIDreaders seen by the sending RFID reader.
 5. The method of claim 1wherein the calibration cycle is repeated multiple times per second. 6.The method of claim 1 wherein each stationary RFID reader in the localarea network maintains a registry of one or more of the other RFIDreaders in the local area network and updates this registry during orafter the calibration cycle.
 7. The method of claim 1 furthercomprising: one or more stationary RFID readers in the local areanetwork sensing that a new stationary RFID reader has entered the localarea network or an RFID reader has moved its position and sending aquery to the new or moved RFID reader to identify itself.
 8. The methodof claim 7 wherein the query also requests a MAC or IP address and arequest that the new or moved RFID reader designate which RFID signaldesignates the new or moved RFID reader.
 9. The method of claim 8wherein upon receiving the responsive RFID signal designating the new ormoved RFID reader, updating a registry of stationary RFID readers. 10.The method of claim 1 wherein the local area network comprises astationary RFID reader at an entrance of a warehouse.
 11. The method ofclaim 1 further comprises updating a registry with the orientation of astationary RFID reader in the local area network.
 12. A networkcomponent comprising: a microcontroller having access to computerreadable memory and computer readable storage, the microcontrolleroperating at a component of a local area network; and, an antenna incommunication with the microcontroller, the antenna configured to atleast transmit or receive radio frequency electro-magnetic waves,wherein the microcontroller is configured to repeatedly spatially locateone or more stationary Radio Frequency Identification (RFID) readers inthe local area network in which the microcontroller is a member, whereinthe microcontroller is further configured to determine the spatiallocation of one or more stationary RFID readers by: using a plurality ofreceived wireless signal responses to a previously sent wireless signal,the received responses from two or more stationary RFID readers in thelocal area network, to determine, using radio frequency telemetry in thelocal area network, the physical distance between each stationary RFIDreader for which a response was received, and wherein themicrocontroller is further configured to exchange with other componentsof the local area network, one or more of the distances betweenstationary RFID readers calculated by other components of the local areanetwork, and to verify the accuracy of these calculated one or moredistances between stationary RFID readers.
 13. The network component ofclaim 12 wherein the microcontroller is further configured to queryknown stationary RFID readers in the local area network and, in responseto this query, determine a physical distance between the networkcomponent and one or more newly added stationary RFID readers.
 14. Thenetwork component of claim 12 wherein the microcontroller is furtherconfigured to receive a unique identifier for a stationary RFID readerfrom an active or passive RFID tag positioned on that stationary RFIDreader.
 15. A non-transitory computer readable medium having storedthereon instructions, which when executed by a microprocessor cause themicroprocessor to carryout steps comprising: repeatedly conducting acalibration cycle to determine the present position of stationaryfiducial Radio Frequency Identification (RFID) readers of a local areanetwork, the stationary RFID readers being stationary when in operation,the calibration cycle including exchanging, between two or more RFIDreaders or other fiducial components of the local area network,distances between two or more RFID readers calculated by one or moreother components of the local area network using radio frequencytelemetry between components of the local area network, and afterreceiving distances in the exchange, verifying the accuracy of theexchanged calculated distances between the stationary RFID readers inthe local area network.
 16. The non-transitory computer readable mediumof claim 15 wherein the calibration cycle includes exchanging betweentwo or more RFID readers, distances between RFID readers calculated byother components of the local area network, and wherein the one or moreother components is a different RFID reader.
 17. The non-transitorycomputer readable medium of claim 15 wherein the instructions storedthereon further cause the microprocessor to carry out steps comprising:sending a radio signal to calibrate the position of the component inwhich the microprocessor resides with each of the other RFID readers inthe local area network.
 18. The non-transitory computer readable mediumof claim 15 wherein the instructions stored thereon further cause themicroprocessor to carry out steps comprising: updating a list of RFIDreaders visible by other RFID readers in the local area network.
 19. Thenon-transitory computer readable medium of claim 15 wherein theinstructions stored thereon further cause the microprocessor to carryout steps comprising: upon receiving a responsive RFID signaldesignating a new or moved RFID reader, updating a registry of RFIDreaders for use by an RFID reader or other component of the local areanetwork.
 20. The non-transitory computer readable medium of claim 15wherein the calibration cycle comprises RFID readers of the local areanetwork exchanging distances between RFID readers of the local areanetwork, the distances calculated by at least one of the RFID readers ofthe local area network.